DAE Problems

DAE Problems

Mathematical Specification of an DAE Problem

To define a DAE Problem, you simply need to give the function $f$ and the initial condition $u₀$ which define an ODE:

\[0 = f(t,u,du)\]

f should be specified as f(t,u,du) (or in-place as f(t,u,du,resid)). Note that we are not limited to numbers or vectors for u₀; one is allowed to provide u₀ as arbitrary matrices / higher dimension tensors as well.

Problem Type

Constructors

DAEProblem{isinplace}(f,u0,du0,tspan) : Defines the DAE with the specified functions. isinplace optionally sets whether the function is inplace or not. This is determined automatically, but not inferred.

Fields

Example Problems

Examples problems can be found in DiffEqProblemLibrary.jl.

To use a sample problem, such as prob_dae_resrob, you can do something like:

#Pkg.add("DiffEqProblemLibrary")
using DiffEqProblemLibrary
prob = prob_dae_resrob
sol = solve(prob,IDA())